1. Field of the Invention
This invention relates to a new and useful amorphous, solid, combination refractory composition and to its synthesis. The new composition is an X-ray amorphous rare earth aluminum phosphorus oxide having high surface area, a unique pore size distribution and which demonstrates thermal and hydrothermal stability. The composition is useful as a catalyst support and provides improvement over prior art supports such as alumina or aluminum phosphate for certain catalytic applications.
2. Discussion of Prior Art
Refractory inorganic materials have been used as catalyst supports for many different catalytic processes. It is common in the catalyst art to observe use of alumina for this purpose, for instance. Other examples of refractory inorganic materials include silica, silica-alumina, clays, crystalline zeolites, oxides of zirconium, titanium, cerium, thorium, lanthanum, calcium and magnesium, and phosphates of zinc, zirconium, thorium, cerium, calcium, magnesium and aluminum. A listing of such materials appears in Australian Pat. No. 31365/84.
Crystalline zeolites, both natural and synthetic, have been demonstrated to be effective catalyst supports. A large variety of synthetic zeolites are known, as illustrated by zeolite A (U.S. Pat. No. 2,882,243), zeolite X (U.S. Pat. No. 2,882,244), zeolite Y (U.S. Pat. No. 3,130,007), zeolite ZK-5 (U.S. Pat. No. 3,247,195), zeolite ZK-4 (U.S. Pat. No. 3,314,752), zeolite ZSM-5 (U.S. Pat. No. 3,702,886), zeolite ZSM-11 (U.S. Pat. No. 3,709,979), zeolite ZSM-12 (U.S. Pat. No. 3,832,449), zeolite ZSM-20 (U.S. Pat. No. 3,972,983), ZSM-35 (U.S. Pat. No. 4,016,245), ZSM-38 (U.S. Pat. No. 4,046,859), and zeolite ZSM-23 (U.S. Pat. No. 4,076,842), merely to name a few.
Aluminum phosphates are taught in U.S. Pat. Nos. 4,310,440; 4,385,994; 4,365,095; 4,361,705; 4,222,896; 4,210,560; 4,179,358; 4,158,621; 4,071,471; 4,014,945; 3,904,550 and 3,697,550, for example. Microporous aluminum phosphates have a composition typified as: EQU xR:Al.sub.2 O.sub.3 :(1.0 0.2)P.sub.2 O.sub.5 :yH.sub.2 O
wherein R is an organic amine or quaternary ammonium salt entrapped within the aluminum phosphate and playing a role as crystallization template, x and y representing the amounts of R and H.sub.2 O needed to fill the microporous voids.
U.S. Pat. No. 4,440,871 teaches material called silicoaluminophosphate without non-aluminum metals. Individual silicophosphoaluminate structures are shown in U.S. Pat. Nos. 4,623,527; 4,632,811 and 4,639,357. An antimonophosphoaluminate structure is taught in U.S. Pat. No. 4,619,818.
The phosphorus-substituted zeolites of Canadian Pat. Nos. 911,416; 911,417 and 911,418 are referred to as "aluminosilicophosphate" zeolites. These latter materials containing silicon, aluminum and phosphorus are characterized by the general formula: EQU M.sub.(x-y) :x(AlO.sub.2.sup.-):(SiO.sub.2):y(PO.sub.2.sup.+):zH.sub.2 O
wherein M is a monovalent cation, x is approximately 0.125-1.5, y is 0.05-1.0 and z is the number of hydration water molecules. Structural replacement of silicon with phosphorus has been realized in materials called silica clathrates (West German Pat. No. 3,128,988). U.S. Pat. No. 4,363,748 describes a combination of silica and aluminum-calcium-cerium phosphate as a low acid activity catalyst for oxidative dehydrogenation. Great Britain Pat. No. 2,068,253 discloses a combination of silica and aluminum-calcium-tungsten phosphate as a low acid activity catalyst for oxidative dehydrogenation. U.S. Pat. No. 3,801,704 teaches an aluminum phosphate treated in a certain way to impart acidity. U.S. Pat. No. 4,228,036 teaches an alumina-aluminum phosphate-silica matrix as an amorphous body to be mixed with zeolite for use as cracking catalyst. U.S. Pat. No. 3,213,035 teaches improving hardness of aluminosilicate catalysts by treatment with phosphoric acid.
U.S. Pat. No. 4,382,877 describes a catalyst composition of a particular metal on a support containing (1) a compound of magnesium, calcium, strontium or barium, (2) alumina and (3) aluminum phosphate, the support having an average pore radius of from 10 to 300 Angstroms, a surface area of from 100 to 350 m.sup.2 /g and a pore volume of from 0.3 to 1.5 cc/g. Various combinations of metal compounds, such as calcium, strontium, barium and magnesium oxide, with alumina and aluminum phosphate are described as catalyst supports in U.S. Pat. No. 4,382,878.
U.S. Pat. No. 4,376,067 describes a catalyst support containing various combinations of metal compounds, including zinc, cadmium, magnesium, calcium, strontium and barium compounds, alumina and aluminum phosphate. Magnesia-alumina-aluminum phosphate support material and its synthesis is described in U.S. Pat. No. 4,210,560. Use of a magnesia-alumina-aluminum phosphate supported catalyst for cracking is described in U.S. Pat. No. 4,179,358. U.S. Pat. No. 3,755,146 describes a high surface area catalyst support material comprising alumina, silica, titania, zirconia, boria and combinations thereof.
U.S. Pat. No. 2,876,266 describes an active silicophosphoric acid or salt phase of an amorphous material prepared by absorption of phosphoric acid by premolded silicates, e.g. aluminosilicates.